#include<iostream>
using namespace std;
int main()
{
    pair< int,double> p1;
    cout << p1.first << "," << p1.second << endl;
    pair< string,int> p2("this",20);
    cout << p2.first << "," << p2.second << endl;
    pair< int,int> p3(pair<char,char>('a','b'));
    cout << p3.first << "," << p3.second << endl;
    pair< int,string> p4 = make_pair(200,"hello");
    cout << p4.first << "," << p4.second << endl;
    return 0;
}
